Notable new features are: better Unicode support, proper support for time after the Y2038 barrier, new APIs to allow developers to extend Perl with 'pluggable' keywords and syntax, warnings for deprecated features and more.

Note that this happens inside the default wp_notify_postauthor function, which is a "pluggable" function, meaning that plugins can override it; see comment_notification_text applied to the body of the mail message before sending email notifying the post author of a new comment.

Note that this happens inside the default wp_notify_moderator function, which is a "pluggable" function, meaning that plugins can override it; see comment_notification_headers applied to the mail headers before sending email notifying the post author of a new comment.